| 摘要: |
| 分析了基于空间矢量脉宽调制(SVPWM)的常规单Z源三电平中点钳位(NPC)逆变器的升压能力，指出若直通矢量作用时间不超过某一有效矢量的作用时间，则逆变器的电压增益最大值仅为1.15，不具备升压能力。对SVPWM方法作出修改，使电压增益与Z源两电平逆变器的相同。为了进一步提高升压能力，提出一种增强型Z源网络，直流母线的正端和负端各引入1个开关电感(SL)单元，不仅提高电压增益，而且在相同电压增益的条件下降低了在Z源网络电容的电压应力，还能实现中点电位平衡。在此基础上又提出了升压能力更强的多单元开关电感增强型Z源网络。仿真结果表明，改进SVPWM方法和新型拓扑对提高Z源三电平NPC逆变器的升压能力十分有效。 |
| 关键词: Z源逆变器 三电平 开关电感 空间矢量脉宽调制 |
| DOI：10.7667/j.issn.1674-3415.2015.16.010 |
| 投稿时间：2014-11-17 |
| 基金项目:广州市科技计划项目(2013J4100017)；广州市属高校科研计划项目(2012A034)；广东省高等学校高层次人才项目(2050205-194) |
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| Enhanced Z-source three-level inverter based on switched-inductor |
| WANG Xiaogang,ZHANG Jie |
| (College of Mechanical and Electronic Engineering, Guangzhou University, Guangzhou 510006, China) |
| Abstract: |
| The voltage boost capability of conventional single Z-source three-level neutral point clamped (NPC) inverter based on space vector pulse width modulation (SVPWM) is analyzed. If the duty time of a shoot through vector is less than that of a particular effective vector, the maximum voltage gain of the inverter will be just 1.15. The inverter has no voltage boost capability. On that basis, the SVPWM method is modified, this results in higher voltage gain which is identical to that of a two-level Z-source inverter. In order to further improve voltage boost capability, an enhanced Z-source network is proposed. Two switched-inductor (SL) units are connected to the positive bus and negative bus respectively to improve the voltage boost gain. This new topology can achieve lower voltage press of Z-source capacitors than the conventional three-level Z-source inverter when they have identical voltage gains, and it makes it possible to implement neutral-point potential balancing control. And then, Multicell SL enhanced Z-source network is proposed, which has stronger voltage boost capability than that of SL based topology. Simulation results show that both the improved SVPWM methods and the new topologies can improve the voltage boost capability of Z-source three-level NPC inverter effectively. |
| Key words: Z-source inverter three-level switched inductor space vector pulse width modulation |
